import java.awt.*;
import javax.swing.*;
public class MainFrame
{
public static void main(String[] args)
{
       
        
        JFrame jf=new JFrame("Jianke");
        jf.setSize(300,300);
        jf.add(new JButton("hello"));
        jf.setVisible(true);
        try
        {
               Thread.sleep(5000);
        }
        catch(Exception e)
        {
               e.printStackTrace();
        }
        jf.setVisible(false);
        jf.dispose();
}
}